While the threat to hormones from the plastic containers is well known, these antiseptic chemicals have also been linked to infertility.

Mice exposed to them were left unable to have babies, and scientists have now found they damage human cells.

Examples of the household products containing quats include Dettol surface cleaner and antibacterial wipes, as well as Tesco disinfectant. But there are many more, including Lemsip Max All In One Liquid and two types of mouthwash from Colgate.

Dr Gino Cortopassi, co-author of a study on the chemicals from the University of California, Davis, said: It is concerning that these everyday household products contain these chemicals, which at a certain concentration have been shown to disrupt fertility in mice and which we have found in cells disrupts the oestrogen-signalling process so important for human fertility.

However we don't yet know what levels these compounds reach in humans.' Quats, used since the 1940s, are good disinfectants because they dissolve the cell membranes of germs found in our homes. They work the same way to kill bugs in our mouths.

But the latest findings suggest they do this by damaging the mitochondria  rod-shaped batteries' which power the cells of these bugs.

This could be dangerous because our cells have the same mitochondria, which in women and men could damage the sex cells needed to start a family. Following studies showing that mice became infertile after being exposed to quats, the US researchers looked at 1,600 compounds containing them. They discovered the chemicals do block human mitochondria and stop them working correctly.

They also affect the hormone oestrogen, which plays a vital part in women falling pregnant. The quats studied include cetylpyridinium chloride, found in products including the Colgate Max White expert toothbrush and whitening pen, as well as Colgate Total Advanced peppermint mouthwash and Colgate Fluorigard alcohol-free mouthwash.

A supermarket search by the Daily Mail also revealed the chemical is an ingredient in Lemsip Max All In One Liquid, recommended for chesty coughs and blocked noses.

A second chemical found to damage human cells is benzalkonium chloride, which appears in Tesco Fresh antiseptic disinfectant and the supermarket's Pro Formula antibacterial hand wipes, as well as Dettol's antibacterial surface cleaner and surface wipes.

The products contain the quats in relatively small amounts, but experts fear they may be building up in people who use more of the large number of products containing them.

As the results are only in cells, they intend to further test quat exposure in people and sex cells.

The study is published in the journal Environmental Health Perspectives.

The British Retail Consortium said the products are strictly controlled to ensure they are safe to use. RB, which makes Lemsip and Dettol, and Colgate were unable to provide a comment.